function checkForm(){
  var name = document.getElementById("name");
  var email = document.getElementById("email");
  if( (name.value == null || email.value == null) || (name.value == '' || email.value == '') ){
    alert("Please, fill in all necessary fields");
    return false;
  } else {
    
    var reg = new RegExp("[0-9a-z_]+@[0-9a-z_^.]+\\.[a-z]{2,3}", 'i');
    if (!reg.test(email.value)) {
        email.style.borderColor="red";
        alert('Invalid email address: '+email.value+' !!!');
        email.focus();
        return false;
    }    
    return true;
  }    
} 

function reset(){
  var name = document.getElementById("name");
  var email = document.getElementById("email");
  var phone = document.getElementById("phone");
  var message = document.getElementById("message");
  
  name.value = null; 
  email.value = null;
  phone.value = null;   
  message.value = null;
}